KR20160080847A - System and Method for Multi-User Multiple Polarized Input Multiple Output(MU-mPIMO) - Google Patents

Abstract

The present invention relates to multiple polarization transmission system and method for wireless communications, capable of transmitting individual data streams to multiple users simultaneously by performing transmission from a multiple polarization input to a multiple output in proportion to the number of polarized antennas used in a transmitter or the number of polarized waves.

Description

Technical Field [0001] The present invention relates to a system and a method for transmitting multiple polarized waves for simultaneous transmission of multiple users.

The present invention relates to a polarization transmission system and method, and more particularly, to a multi-polarization transmission system and method capable of simultaneously transmitting an individual data stream to multiple users by transmitting from multiple polarization input to multiple outputs.

In a conventional system for transmitting data using polarization in a line-of-sight channel environment, a transmitter may transmit data with a large number of polarized antennas, or a plurality of different polarizations may be used to transmit information , The polarization channel of this system has a degree of freedom of two. Such a conventional transmitter for polarization transmission transmits individual data streams to only a maximum of two users irrespective of the number of polarized antennas and the number of polarizations used, so that it is possible to transmit individual data streams to a larger number of users Is required.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a multi- And to provide a multi-polarization transmission system and method for wireless communication capable of simultaneously transmitting individual data streams.

In order to achieve the above object, a transmitter for transmitting a plurality of polarized waves, each of which transmits a data stream to a plurality of receivers using a polarized wave signal according to an aspect of the present invention, A multiplexed polarized signal generating unit for converting the data streams to be transmitted into N polarized signals orthogonal to each other and synthesizing them; And an RF (Radio Frequency) unit for frequency up-converting the synthesized N polarized signals and transmitting the converted signals through a transmission antenna.

N receivers may receive different data streams according to the N polarized signals transmitted through one transmission antenna.

According to another aspect of the present invention, there is provided a mobile communication system including M M polarization signal generators and M M RF antennas, Stream can be received.

을 계산하여 코딩하되, 여기서,The multi-polarized wave signal generator generates a multi-polarized wave signal by multiplying the N polarized signal x = (x ₁ x _{2 ..} x _N ) ^T by a precoder matrix

Lt; RTI ID = 0.0 > 1, < / RTI &

,

,

_{H 1, H 1, ..,} H N is the channel matrix including channel line-of-sight and non-line of sight component for each channel of the N polarization ^{_{signal, ω 1 (i), ω}} 2 (i), .. ω N (i ⁾ Is a repetition number i-th received signal combiner column vector for each channel of the N polarized wave signals.

을 만족할 때까지 상기 프리코더 행렬을 반복적으로 계산하고, 여기서The multiplexed polarized signal generating unit may multiply the predetermined error value epsilon by a predetermined number of times of the repetition number i or based on the received signal combiner column vector _m ^{(i + 1)} at the corresponding receiver m

Lt; RTI ID = 0.0 > a < / RTI > precoder matrix,

,

,

H _m is the channel matrix for the receiver m, v _m ^{(i + 1)} is (i + 1) th precoders matrices V m-th column, () in the ^{(i + 1) *} is the complex conjugate, ∥ ∥ ₂ is the vector magnitude of to be.

에 대하여, 프리코더 행렬

을 계산하여 코딩하되, 여기서,In addition, when the M polarized wave signal generating unit and M RF receiving units are provided, each of the M polarized wave signal generating units may generate the MN polarized wave signal

, A precoder matrix

Lt; RTI ID = 0.0 > 1, < / RTI &

,

,

₁,

₂,..,

_MN은 상기 MN개의 편파 신호 각 채널에 대하여 가시선 및 비가시선 채널 성분을 포함한 채널 행렬, ω₁ ⁽ⁱ⁾, ω₂ ⁽ⁱ⁾,.. ω_MN ⁽ⁱ⁾는 상기 MN개의 편파 신호 각 채널에 대하여 반복횟수 i번째 수신 신호 컴바이너 열벡터이다.

₁ ,

₂ , ...,

_MN is a channel matrix including visible and invisible channel components for each of the MN polarized signal channels, ω ₁ ⁽ⁱ⁾ , ω ₂ ⁽ⁱ⁾ , ω _MN ⁽ⁱ⁾ I is the ith received signal combiner row vector.

을 만족할 때까지 상기 프리코더 행렬을 반복적으로 계산하고, 여기서Based on the received signal combiner column vector ω _m ^{(i + 1)} at the receiver m or the predetermined error value ε up to the preset number of iterations i,

Lt; RTI ID = 0.0 > a < / RTI > precoder matrix,

,

,

_m은 수신기m에 대한 채널 행렬, v_m ⁽ⁱ⁺¹⁾는 i+1번째 프리코더 행렬 V⁽ⁱ⁺¹⁾의 m번째 열, ()^*는 공액 복소수, ∥ ∥₂는 벡터의 크기이다.

_m is the channel matrix for the receiver m, v _m ^{(i + 1)} is (i + 1) th precoders m-th column of the matrix ^{V (i + 1), (} ) * is the size of the complex conjugate, ∥ ∥ ₂ is a vector .

In another aspect of the present invention, there is provided a multi-polarization transmission method for transmitting a data stream to a plurality of receivers using a multi-polarization signal in a transmitter, the multi-polarization transmission method comprising the steps of: converting N transmission data streams into N polarized signals orthogonal to each other; ; And a step of frequency up-converting the synthesized N polarized wave signals and transmitting the up-converted signals through a transmission antenna.

N receivers may receive different data streams according to the N polarized signals transmitted through one transmission antenna.

Also, MN receivers can receive different data streams according to corresponding polarized signals of MN transmitted through the N polarized signals through each of the M transmission antennas.

을 계산하여 코딩하되, 여기서,In the transforming and combining step, for the N polarized signals x = (x ₁ x _{2 ..} x _N ) ^T , a precoder matrix

Lt; RTI ID = 0.0 > 1, < / RTI &

,

,

_{H 1, H 1, ..,} H N is the channel matrix including channel line-of-sight and non-line of sight component for each channel of the N polarization ^{_{signal, ω 1 (i), ω}} 2 (i), .. ω N (i ⁾ Is a repetition number i-th received signal combiner column vector for each channel of the N polarized wave signals.

을 만족할 때까지 상기 프리코더 행렬을 반복적으로 계산하고, 여기서Based on the received signal combiner column vector ω _m ^{(i + 1)} at the receiver m or the predetermined error value ε up to the preset number of iterations i,

Lt; RTI ID = 0.0 > a < / RTI > precoder matrix,

,

,

H _m is the channel matrix for the receiver m, v _m ^{(i + 1)} is (i + 1) th precoders matrices V m-th column, () in the ^{(i + 1) *} is the complex conjugate, ∥ ∥ ₂ is the vector magnitude of to be.

에 대하여, 프리코더 행렬

을 계산하여 코딩하되, 여기서,Also, in order to transmit a total of MN polarized signals by N polarized signals through each of the M transmission antennas, in the converting and combining step,

, A precoder matrix

Lt; RTI ID = 0.0 > 1, < / RTI &

,

,

₁,

₂,..,

_MN은 상기 MN개의 편파 신호 각 채널에 대하여 가시선 및 비가시선 채널 성분을 포함한 채널 행렬, ω₁ ⁽ⁱ⁾, ω₂ ⁽ⁱ⁾,.. ω_MN ⁽ⁱ⁾는 상기 MN개의 편파 신호 각 채널에 대하여 반복횟수 i번째 수신 신호 컴바이너 열벡터이다.

₁ ,

₂ , ...,

_MN is a channel matrix including visible and invisible channel components for each of the MN polarized signal channels, ω ₁ ⁽ⁱ⁾ , ω ₂ ⁽ⁱ⁾ , ω _MN ⁽ⁱ⁾ I is the ith received signal combiner row vector.

을 만족할 때까지 상기 프리코더 행렬을 반복적으로 계산하고, 여기서Based on the received signal combiner column vector ω _m ^{(i + 1)} at the receiver m or the predetermined error value ε up to the preset number of iterations i,

Lt; RTI ID = 0.0 > a < / RTI > precoder matrix,

,

,

_m은 수신기m에 대한 채널 행렬, v_m ⁽ⁱ⁺¹⁾는 i+1번째 프리코더 행렬 V⁽ⁱ⁺¹⁾의 m번째 열, ()^*는 공액 복소수, ∥ ∥₂는 벡터의 크기이다.

_m is the channel matrix for the receiver m, v _m ^{(i + 1)} is (i + 1) th precoders m-th column of the matrix ^{V (i + 1), (} ) * is the size of the complex conjugate, ∥ ∥ ₂ is a vector .

According to the multi-polarization transmission system and method for wireless communication according to the present invention, in a multi-user environment, the transmitter can simultaneously transmit an arbitrary number of different polarized signals without performance deterioration. Therefore, the total transmission capacity of the wireless communication system can be remarkably improved. That is, if the transmitter of the present invention transmits N different polarized signals through the respective antennas, the total transmission capacity can be increased by N times the conventional system. Further, the number N of usable polarizations can be arbitrarily increased according to the design.

FIG. 1 is a diagram for explaining a multi-polarization single antenna system for transmission to multiple users according to an embodiment of the present invention. Referring to FIG.
2A is a structural diagram of the transmitter of FIG.
2B is a structural diagram of the receiver of FIG.
2C is a flow chart for explaining the operation of the multi-polarization single-antenna system of FIG.
3 is a graph illustrating an example of the total throughput performance when using four polarizations in the multi-polarization single-antenna system of FIG.
4 is a diagram for explaining a multi-polarization multi-antenna system for transmission to multiple users according to another embodiment of the present invention.
5A is a structural diagram of the transmitter of FIG.
5B is a structural diagram of the receiver of FIG.
5C is a flow chart for explaining the operation of the multi-polarization single-antenna system of FIG.
6 is an exemplary diagram for transmission to four users in the multi-polarization multi-antenna system of FIG.
7 is a graph illustrating an example of total throughput performance for the multi-polarization multi-antenna system of FIG.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same components are denoted by the same reference symbols as possible. In addition, detailed descriptions of known functions and / or configurations are omitted. The following description will focus on the parts necessary for understanding the operation according to various embodiments, and a description of elements that may obscure the gist of the description will be omitted. Also, some of the elements of the drawings may be exaggerated, omitted, or schematically illustrated. The size of each component does not entirely reflect the actual size, and therefore the contents described herein are not limited by the relative sizes or spacings of the components drawn in the respective drawings.

The present invention relates to a multi-polarized single antenna system (see FIGS. 1-3) for simultaneously transmitting an individual data stream to each wireless communication receiver of a plurality of users via a single or multiple antennas capable of transmitting multi-polarized signals in a transmitter for wireless communication ) And a multi-polarization multi-antenna system (see Figs. 4-7).

In the present invention, the multi-polarized signal may be a signal for wireless mobile communication according to a protocol such as WCDMA or LTE, or may be a signal for wireless short-distance communication such as WiFi, Bluetooth, ZigBee, May also be extended.

Accordingly, the transmitter or the receiver may be a transmitter or a receiver mounted in a mobile terminal such as a base station, an access point (AP), a mobile phone, etc. for wireless communication such as wireless mobile communication or wireless local area communication.

1 is a block diagram illustrating a multi-polarization single-antenna system for transmission to multiple users according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 1, a multi-polarization single-antenna system according to an embodiment of the present invention includes a transmitter 100 that transmits N (natural number) polarized signals using one transmission antenna, and a dual- And a receiver 200 for receiving the polarized signal transmitted from the transmission antenna. The receiver 200 includes N receivers RX ₁ , RX ₂ , .. RX _N and is used to simultaneously transmit signals to individual N receivers RX ₁ , RX ₂ , ... RX _N simultaneously using N polarized signals, Data streams can be transmitted.

Hereinafter, for the description of the transmission method of the present invention, a scenario is described in which one data stream is transmitted through one polarized signal per user to each of N receivers (RX ₁ , RX ₂ , .. RX _N ) of a maximum of N users However, the present invention is not limited thereto and can be extended to transmit two data streams separated by two different polarizations to each user receiver according to the receiver configuration.

2A is a structural diagram of the transmitter 100 of FIG. 2B is a structural diagram of the receiver 200 of FIG. 2A, the transmitter 100 includes a multipole signal generating unit 110 and an RF (Radio Frequency) unit 120. Each receiver 200 includes an RF (Radio Frequency) unit 210 and a signal detection and recovery unit 220. The RF unit 210 may be composed of two or more RF units for processing two or more different polarizations to receive the two separated data streams.

In the transmitter 100, a multi-polarized signal generator 110 includes N number of transmission target data stream _{d 1, d 2, ..,} N two polarization signals of a baseband corresponding to a d _N thereof (x _1, x _2, ... x _N ) and synthesized. The N polarized signals (x ₁ , x ₂ , ... x _N ) orthogonal to each other form N channels having transmission polarization angles of θ ₁ , θ ₂ , .. θ _N between neighboring signals according to a predetermined algorithm . The RF unit 120 up-converts the signal synthesized by the polarized wave signal generator 110 and transmits the up-converted signal through one transmission antenna.

In the receiver 200, each RF unit 210 (e.g., the mth RX _m ) receives a signal of a corresponding channel for each data stream transmitted from the transmitter 100 via one dual polarized antenna (e.g., coordinate system and ^{_{y m (v), y m}} (h) receiving polarization receive signals) having the respective θ _R and conversion (down-conversion) to a frequency-down signal of the baseband from. The signal detection and recovery unit 220 estimates and restores the original data stream from the output of each RF unit 210. [

A substantial line-of-sight channel environment between the transmitter 100 and the receiver 200 is that the line-of-sight channel component is much larger but contains a weak non-line-of-sight channel component It is common. Accordingly, as described below, by appropriately adjusting the Rician channel model and the K factor value of the model, the 2xN channel matrix H _m in the m-th receiver RX _m as in Equation (1) Channel environment can be expressed well.

[Equation 1]

는 송신기(100)의 안테나에서 m번째 수신기(RX_m) 안테나로의 2xN 가시선 채널 성분 행렬이고,

는 송신기(100) 안테나에서 m번째 수신기(RX_m) 안테나로의 2xN 비가시선 채널 성분 행렬을 나타낸다. 또한, K는 가시선 채널 성분 전력의 크기를 결정하는 파라미터이다. here

Is a 2xN line component channel matrix from the antenna of the transmitter 100 to the mth receiver (RX _m ) antenna,

Represents a 2xN non-spectral channel component matrix from the transmitter 100 antenna to the mth receiver (RX _m ) antenna. Also, K is a parameter for determining the magnitude of the power of the visible channel component.

을 표현하면 [수학식2]와 같다. Based on the parameters given in Fig. 1,

Is expressed by Equation (2).

&Quot; (2) "

는 고정된 값으로 나타낼 수 없고 통계적인 특성으로 나타낼 수 있다. 편파 신호의 각도, 반사 그리고 산란 특성 등을 고려하여 비가시선 채널 성분의 통계적 평균(E) 특성인 채널 상관관계 행렬

은 [수학식3]과 같이 간략히 근사화할 수 있다. 이때 벡터(vec)

는

을 의미한다. T는 transpose로서, 행과 열을 바꾸는 함수.In addition,

Can not be represented by a fixed value but can be represented by a statistical characteristic. The channel correlation matrix (E), which is the statistical mean (E) characteristic of the non-invisible channel components in consideration of the angle,

Can be approximated as shown in Equation (3). The vector (vec)

The

. T is a transpose function that replaces rows and columns.

&Quot; (3) "

Here, I _? Is given by Equation (4), and? Is a constant indicating the channel correlation of the non-sighted channel component satisfying 0?? 1.

&Quot; (4) "

1, the reception signal y _m of the _mth receiver RX _m can be expressed by Equation (5). Where x = (x ₁ x _{2 ..} x _N ) ^T is the vector of the transmitted polarization signal and z _m is the Gaussian white noise vector at the mth receiver.

&Quot; (5) "

On the other hand, the transmitter 100 multi-polarized wave signal generation unit 110 generates channel information (e.g., polarized signals x ₁ , x ₂ ( _n )) of the polarized wave signals fed back from the _N receivers RX ₁ , RX ₂ , x 2 _N , ... x _N ) in accordance with a predetermined channel identifier (e.g., a channel identifier corresponding to the received signal x ₁ , x ₂ , ... x _N ), and transmits the precoded signal through a precoder By transmitting target data streams, each receiver (RX ₁ , RX ₂ , .. RX _N ) is able to receive its desired respective data stream without interference. In addition, each of the receivers RX ₁ , RX ₂ , .., RX _N applies various receiving signal combining methods such as maximal ratio combining to signals received through respective polarizations of the receiving antenna, .

Therefore, the transmitter 100 and the mth receiver (R _xm ) of FIG. 1 must determine the NxN precoder matrix V and the 2x1 signal combiner column vector _m, respectively. The transmitter 100 precoder matrix and the receiver 200 signal combiner column vectors are transmitted from the transmitter 100 to the transmitter 100 when the antenna 100 transmits using any of the N polarized signals, Can be obtained using the following iterative procedure. Here, reference is made to the flow chart of FIG. 2C.

에 임의의 행렬

을 할당하여 초기 수신 신호 컴바이너 열벡터

을 [수학식6]과 같이 구한다(S10).First, i, which indicates the number of repetitions, is set to 0, and an initial precoder matrix

An arbitrary matrix

To assign the initial received signal combiner column vector

Is obtained as shown in Equation (6) (S10).

&Quot; (6) "

는 i번째 프리코더 행렬 V⁽ⁱ⁾의 m번째 열을, ()^*는 공액 복소수를, || ||₂는 벡터의 크기를 각각 의미한다.here,

^(I) is the m-th column of the i-th precoder matrix V ⁽ⁱ⁾ , () ^* denotes a conjugate complex number, || ₂ denotes the size of the vector, respectively.

을 구한다(S11).Next, as shown in Equation (7)

(S11).

&Quot; (7) "

Next, the (i + 1) -th precoder matrix V ^{(i + 1)} is obtained by using various schemes such as a zero-forcing beam forming or a minimum mean square error beam forming technique (S12). For example, when a zero-forcing beam forming technique is applied, Equation (8) is given.

&Quot; (8) "

Next, the (i + 1) th received signal combiner column vector ω _m ^{(i + 1)} is obtained according to the selected received signal combining method (S13). For example, when the (i + 1) th received signal combiner column vector is obtained according to the maximum ratio combining method, Equation (9) is given.

&Quot; (9) "

을 만족하면 알고리즘을 종료하고 그렇지 않으면 반복 회수를 1만큼 증가시켜 상기의 S11 단계로 돌아가서, 상기 조건을 만족하도록 실행을 반복한다(S14). Finally, if the number of repetitions i exceeds the preset number of times,

The algorithm is terminated. Otherwise, the number of iterations is incremented by one, and the process returns to step S11, and the process is repeated to satisfy the condition (S14).

This algorithm is performed in the transmitter 100 multi-polarized signal generator 110 to determine the precoder matrix V of the transmitter 100. On the other hand, the receiver 200 acquires the channel information based on the pilot signal transmitted through the precoder determined by the transmitter 100, and does not need to perform the algorithm, and generates a signal combiner column vector Data can be restored.

3 is a graph illustrating an example of the total throughput performance when using four polarizations in the multi-polarization single-antenna system of FIG.

3, when transmitting individual data streams to each user of four users using four polarizations in the transmitter 100, the angles of the four polarizations θ ₁ , θ ₂ , θ ₃ , and θ ₄ are both 45 ^o (Bps / Hz) according to the ρ value indicating the channel correlation of the non-luminescent channel component given in Equation (3) when the same and the visible channel component occupies about 90.9% (K = 10) Respectively. At this time, the precoder matrix of the transmitter 100 is obtained by using a zero-forcing beamforming (ZF-BF) technique and the received signal combiner column vector of the receiver 200 is acquired Respectively.

As shown in FIG. 3, the multi-polarization transmission scheme for multi-user simultaneous transmission of the present invention acquires a degree-of-freedom (DoF) performance of 4, which is equal to the number of used polarization, in a high SNR (Signal to Noise Ratio) It is possible to simultaneously transmit individual data streams to all four users without performance degradation. In addition, the system of the present invention achieves a significantly higher total transmission rate than a single input single output (SISO), which is a transmission method, to a single user using a conventional single polarization.

4 is a diagram for explaining a multi-polarization multi-antenna system for transmission to multiple users according to another embodiment of the present invention.

4, a multi-polarization multi-antenna system according to another embodiment of the present invention includes a transmitter 300 for transmitting N (natural number) polarized signals using M (natural number) transmit antennas, And a receiver 400 for receiving a polarized signal transmitted from the transmission antenna using a polarized antenna. The receiver 400 includes MN receivers RX ₁ , RX ₂ , ... RX _MN and uses MN polarized signals to transmit each of the MN's receivers RX ₁ , RX ₂ , ... RX _MN simultaneously Data streams can be transmitted. 4 shows an example of a system for simultaneously transmitting an individual data stream to a plurality of users of an MN through M (natural number) antennas capable of transmitting a multi-polarized signal in the transmitter 300. FIG.

Hereinafter, to explain the transmission method of the present invention, a scenario is described in which one data stream is transmitted through one polarized signal per user to each of the receivers (RX ₁ , RX ₂ , .. RX _MN ) However, the present invention is not limited thereto and can be extended to transmit two data streams separated by two different polarizations to each user receiver according to the receiver configuration.

5A is a structural diagram of the transmitter 300 of FIG. 5B is a structural diagram of the receiver 400 of FIG. 5A, the transmitter 300 includes a M polarization signal generating unit 310 and an RF unit 320 in each of M transmission modules for transmitting N polarized signals. As shown in FIG. 5B, 400 includes a radio frequency (RF) unit 410 and a signal detection and recovery unit 420. The RF unit 210 may be composed of two or more RF units for processing two or more different polarizations to receive the two separated data streams.

In the transmitter 300, each of the M polarization signal generators 310 corresponds to N transmission data streams (e.g., d ₁ ⁽¹⁾ , d ₂ ⁽¹⁾ , .., d _N ⁽¹⁾ (E.g., x ₁ ⁽¹⁾ , x ₂ ⁽¹⁾ ,... X _N ⁽¹⁾ ) of the baseband. The N polarized signals perpendicular to each other (for ^{_{example, x 1 (1), x}} 2 (1), .. x N (1)) is θ ^{_{1 (1)}} between neighboring signals in accordance with a predetermined algorithm, θ ₂ ⁽¹⁾ , ..., _N ⁽¹⁾ are formed. Each of the RF units 320 up-converts the signal synthesized by the polarized wave signal generator 310 and transmits the up-converted signal through the corresponding transmission antenna.

In the receiver 400, each RF unit 410 (e.g., the mth RX _m ) receives a signal for each data stream transmitted from the transmitter 300 via one dual polarized antenna (e.g., receiver side coordinate system y _m ^(v), receive y _m received at the ^(h) polarized signals having respective θ _R), and conversion (down-conversion) to a frequency-down signal of the baseband. The signal detection and recovery unit 420 estimates and restores the original data stream from the output of each RF unit 410.

A substantial line-of-sight channel environment between the transmitter 100 and the receiver 200 is that the line-of-sight channel component is much larger but contains a weak non-line-of-sight channel component It is common. Therefore, by appropriately adjusting the Rician channel model and the K factor value of the model as described below, the channel matrix H _m in the m-th receiver RX _m as in Equation (1) The environment can be expressed well.

을 구성할 수 있다.In this case, when a 2xN channel matrix between the n-th transmit antenna and the m-th receiver (Rx _m ) antenna of FIG. 4 is denoted by H _mn and a Rician channel model is considered as shown in Equation (10) In the same way as the antenna system, a matrix expressing the channel component of the line of sight in consideration of the transmission polarization angle and the reception polarization angle

. ≪ / RTI >

&Quot; (10) "

은, 편파 신호의 각도, 반사 그리고 산란 특성 등을 고려하여 다중 편파 단일 안테나 시스템에서 구해진 단일 송신 안테나에서 전송된 편파에 의해 생성된 채널 간 상관관계와 송신 안테나 간 채널 상관관계 등을 모두 고려하여 구해질 수 있다. 여기서

이고

을 나타낸다. 또한,

라 표시할 때, 그림 4에서 m번째 수신기(RX_m)의 수신 신호 y_m은 [수학식11]과 같다.Also, in case of a non-visible channel component, it can be expressed as a statistical characteristic instead of a fixed channel value. The channel correlation matrix, which is the statistical characteristic of such non-

Considering both the channel correlation generated by the polarization transmitted from a single transmit antenna and the channel correlation between transmit antennas, which are obtained in a multi-polarization single antenna system considering the angle, reflection and scattering characteristics of the polarization signal, . here

ego

. Also,

The received signal y _m of the _mth receiver RX _m in FIG. 4 is expressed by Equation (11).

&Quot; (11) "

는 전송 신호 벡터이고 z_m는 m번째 수신기(RX_m)에서의 가우시안 백색 잡음 벡터를 의미한다.At this time,

Is the transmitted signal vector and z _m is the Gaussian white noise vector at the _mth receiver RX _m .

4, the transmitter 300 determines a precoder based on the channel information (e.g., channel identifier, etc.) of the fed back polarized signal from the _MN's receivers RX ₁ , RX ₂ , ... RX _MN , So that each receiver (RX ₁ , RX ₂ , ... RX _MN ) can receive their desired data without interference. Each of the receivers RX ₁ , RX ₂ , .. RX _MN applies various receiving signal combining methods such as maximal ratio combining to the signals received through the respective polarizations of the receiving antenna, .

Therefore, the transmitter 300 in a 4 and a m-th receiver (RX _m) is not to be determined, respectively MNxMN precoder matrices V and the signal combiner 2x1 column vector ω _m. The transmitter precoder matrix and the receiver signal combiner column vector are transmitted in the same manner as the above-described operation of the multi-polarization single-antenna system in the case of transmitting using the N polarized signals per arbitrary M transmit antennas and the transmit antennas, Can be obtained by using the following iterative execution procedure in the unit 110. [ Here, reference is made to the flow chart of FIG. 5C.

에 임의의 행렬

을 할당하여 초기 수신 신호 컴바이너 열벡터

을 [수학식12]과 같이 구한다(S20).First, i, which indicates the number of repetitions, is set to 0, and an initial precoder matrix

An arbitrary matrix

To assign the initial received signal combiner column vector

Is obtained as shown in [Equation 12] (S20).

&Quot; (12) "

는 i번째 프리코더 행렬 V⁽ⁱ⁾의 m번째 열을, ()^*는 공액 복소수를, ∥ ∥₂는 벡터의 크기를 각각 의미한다.here,

Denotes a m-th column of an i-th precoder matrix V ⁽ⁱ⁾ , () ^* denotes a conjugate complex number, and ₂ denotes a vector size.

을 구한다(S21).Next, as shown in Equation (13)

(S21).

 &Quot; (13) "

Next, the (i + 1) -th precoder matrix V ^{(i + 1)} is obtained by using various schemes such as a zero-forcing beam forming or a minimum mean square error beam forming technique (S22). For example, when a zero-forcing beam forming technique is applied, Equation (14) is given.

&Quot; (14) "

Next, (i + 1) th received signal combiner column vector ω _m ^{(i + 1)} is obtained according to the selected received signal combining method (S23). For example, when the (i + 1) th received signal combiner column vector is obtained according to the maximum ratio combining method, Equation (15) is given.

&Quot; (15) "

을 만족하면 알고리즘을 종료하고 그렇지 않으면 반복 회수를 1만큼 증가시켜 상기의 S21 단계로 돌아가서, 상기 조건을 만족하도록 실행을 반복한다(S24). Finally, if the number of repetitions i exceeds the preset number of times,

The algorithm is terminated. Otherwise, the number of iterations is incremented by 1, and the process returns to step S21 to repeat the execution of step S24 so as to satisfy the above condition (S24).

This algorithm is performed in the transmitter 100 multi-polarized signal generator 110 to determine the precoder matrix V of the transmitter 100. On the other hand, the receiver 200 acquires channel information based on the pilot signal transmitted through the precoder determined in the transmitter 100, and performs a similar process to obtain a signal combiner column vector Data can be restored.

6 is an exemplary diagram for transmission to four user receivers in the multi-polarization multi-antenna system of FIG.

The system of FIG. 6 is similar to the system of FIG. 4 except that M = 2 and N = 2 in the system of FIG. 4, i.e. two transmit antennas (M = 2) Polarized waves) to transmit the individual data streams to each receiver of four users. In this case, orthogonal polarization is used in the individual transmission antennas and the channel component of the line of sight occupies about 90.9% (K = 10).

이다. Considering the statistical characteristics of the non-visible channel components, the inter-channel correlation generated by the polarized waves transmitted from the individual transmission antennas follows Equation (3), and the intervals between the transmission antennas and the intervals between the receivers are sufficiently secured, It is assumed that correlation between channels from other transmission antennas to each reception antenna and correlation between channels from each transmission antenna to different reception antennas are not considered. That is, when k ≠ m or l ≠ n

to be.

In this system environment, an example of a graph of the total rate performance according to the value of r representing the channel correlation of the nonvisual channel components given in Equation (3) is shown in FIG. Here, the precoder matrix of the transmitter 300 is obtained using a zero-forcing beamforming (ZF-BF) technique, and the receiver signal combiner column vector of the receiver is obtained by applying a maximum ratio combining method .

7, the scheme of the present invention achieves a DoF performance of 4, which is equal to the product of the number of transmit antennas (M = 2) used in the high SNR region and the number of polarization per transmit antenna (N = 2) It is possible to simultaneously transmit individual data streams to all four users without degradation. In addition, the system of the present invention achieves a significantly higher total transmission rate than a multi-user multiple output multiple input (MU-MIMO) system that transmits to two users using a single polarization in two existing transmit antennas can confirm.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the essential characteristics of the invention. Therefore, the spirit of the present invention should not be construed as being limited to the embodiments described, and all technical ideas which are equivalent to or equivalent to the claims of the present invention are included in the scope of the present invention .

The transmitters 100 and 300,
The multi-polarized wave signal generators 110 and 310,
RF (Radio Frequency) units 120 and 320,
Receivers 200 and 400,
RF (Radio Frequency) units 210 and 410,
The signal detection and recovery units 220 and 420,

Claims (14)

CLAIMS What is claimed is: 1. A transmitter for multi-polarization transmission, which transmits a respective data stream to a plurality of receivers using a multi-polarized signal,
A multiplexed polarization signal generator for converting the N transmission data streams into N polarized signals orthogonal to each other and synthesizing them; And
An RF (Radio Frequency) unit for frequency up-converting the synthesized N polarized wave signals and transmitting the frequency-
And a transmitter for transmitting the multi-polarized wave. The method according to claim 1,
And N receivers each receive a different data stream according to the N polarized signals transmitted through one of the transmission antennas. The method according to claim 1,
M number of polarized wave signal generators and M number of RF antennas, each of the MN receivers receiving a different data stream according to corresponding polarized signals of MN transmitted through the N polarized signals through each of the M transmit antennas And transmitting the multiplexed data to the transmitter. The method according to claim 1,
The multi-polarized wave signal generator generates a multi-polarized wave signal by multiplying the N polarized signal x = (x ₁ x _{2 ..} x _N ) ^T by a precoder matrix

Lt; RTI ID = 0.0 > 1, < / RTI &

,
_{H 1, H 1, ..,} H N is the channel matrix including channel line-of-sight and non-line of sight component for each channel of the N polarization ^{_{signal, ω 1 (i), ω}} 2 (i), .. ω N (i ⁾ Is a repetition number i-th received signal combiner column vector for each channel of the N polarized wave signals. 5. The method of claim 4,
The multiplexed polarized signal generating unit may multiply the predetermined error value epsilon by a predetermined number of times of the repetition number i or based on the received signal combiner column vector _m ^{(i + 1)} at the corresponding receiver m

Lt; RTI ID = 0.0 > a < / RTI > precoder matrix,

,
H _m is the channel matrix for the receiver m, v _m ^{(i + 1)} is (i + 1) th precoders matrices V m-th column, () in the ^{(i + 1) *} is the complex conjugate, ∥ ∥ ₂ is the vector magnitude of And a transmitter for transmitting the multi-polarized wave. The method according to claim 1,
When the M polarized wave signal generating unit and M RF units are provided,
Each of the multi-polarized wave signal generators includes:

, A precoder matrix

Lt; RTI ID = 0.0 > 1, < / RTI &

,

₁ ,

₂ , ...,

_MN is a channel matrix including visible and non-visible channel components for each of the MN polarized signal channels, ω ₁ ⁽ⁱ⁾ , ω ₂ ⁽ⁱ⁾ , ω _MN ⁽ⁱ⁾ And the i-th received signal is a column vector. The method according to claim 6,
Based on the received signal combiner column vector ω _m ^{(i + 1)} at the receiver m or the predetermined error value ε up to the preset number of iterations i,

Lt; RTI ID = 0.0 > a < / RTI > precoder matrix,

,

_m is the channel matrix for the receiver m, v _m ^{(i + 1)} is (i + 1) th precoders matrices V ^{(i + 1),} m-th column, () ^* is the complex conjugate, of ∥ ∥ ₂ is the magnitude of the vector Wherein the first and second polarized waves are transmitted to the transmitter. A multi-polarization transmission method for transmitting a data stream to a plurality of receivers using a multi-polarized signal at a transmitter,
Transforming the N transmission data streams into N polarized signals orthogonal to each other and synthesizing them; And
Up-converting the synthesized N polarized signals and transmitting the up-converted signals through a transmission antenna
And transmitting the multiplexed polarized wave. 9. The method of claim 8,
Wherein the N receivers receive different data streams according to the N polarized signals transmitted through one transmission antenna. 9. The method of claim 8,
Wherein each of the MN receivers receives different data streams according to corresponding polarized signals of MN transmitted through the N polarized signals through the M transmission antennas. 9. The method of claim 8,
In the converting and synthesizing step,
For the N polarized signals x = (x ₁ x _{2 ..} x _N ) ^T , a precoder matrix

Lt; RTI ID = 0.0 > 1, < / RTI &

,
_{H 1, H 1, ..,} H N is the channel matrix including channel line-of-sight and non-line of sight component for each channel of the N polarization ^{_{signal, ω 1 (i), ω}} 2 (i), .. ω N (i ⁾ Is a repetition number i-th received signal combiner column vector for each channel of the N polarized wave signals. 12. The method of claim 11,
Based on the received signal combiner column vector ω _m ^{(i + 1)} at the receiver m or the predetermined error value ε up to the preset number of iterations i,

Lt; RTI ID = 0.0 > a < / RTI > precoder matrix,

,
H _m is the channel matrix for the receiver m, v _m ^{(i + 1)} is (i + 1) th precoders matrices V m-th column, () in the ^{(i + 1) *} is the complex conjugate, ∥ ∥ ₂ is the vector magnitude of And the second polarized wave is a polarized wave. The method according to claim 1,
In order to transmit a total of MN polarized signals by N polarized signals through each of the M transmission antennas,
In the converting and synthesizing step,
The MN's polarized signals

, A precoder matrix

Lt; RTI ID = 0.0 > 1, < / RTI &

,

₁ ,

₂ , ...,

_MN is a channel matrix including visible and invisible channel components for each of the MN polarized signal channels, ω ₁ ⁽ⁱ⁾ , ω ₂ ⁽ⁱ⁾ , ω _MN ⁽ⁱ⁾ And the i-th received signal is a combinator column vector. 14. The method of claim 13,
Based on the received signal combiner column vector ω _m ^{(i + 1)} at the receiver m or the predetermined error value ε up to the preset number of iterations i,

Lt; / RTI > the precoder matrix < RTI ID = 0.0 >

,

_m is the channel matrix for the receiver m, v _m ^{(i + 1)} is (i + 1) th precoders matrices V ^{(i + 1),} m-th column, () ^* is the complex conjugate, of ∥ ∥ ₂ is the magnitude of the vector Wherein the polarized wave transmission method comprises the steps of:

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